<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Infinite Stairway CSS Animation Effects</title>
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <div class="window">
      <div class="stair">
        <span style="--i: 1"></span>
        <span style="--i: 2"></span>
        <span style="--i: 3"></span>
        <span style="--i: 4"></span>
        <span style="--i: 5"></span>
        <span style="--i: 6"></span>
        <span style="--i: 7"></span>
        <span style="--i: 8"></span>
        <span style="--i: 9"></span>
        <span style="--i: 10"></span>
      </div>
    </div>
  </body>
</html>
